Sphincter treatment apparatus

ABSTRACT

A sphincter treatment apparatus includes an elongated member having at least one lumen including an inflation lumen and a basket assembly with first and second arms. The basket assembly is coupled to the elongated member and has deployed and non-deployed configurations. An inflatable member is coupled to the elongated member and positioned in an interior of the basket assembly. The inflatable member has deployed and non-deployed states and is coupled to the inflation lumen. In the deployed state, the inflatable member expands the basket assembly to its deployed configuration. A first energy delivery device is positionable in the first arm and advanceable from the first arm to a selected treatment site. A second energy delivery device is positionable in the second arm and advanceable from the second arm to a selected treatment site.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.09/776,140, filed Feb. 2, 2001, now U.S. Pat. No. 6,673,070, which is acontinuation of U.S. application Ser. No. 09/235,060, filed Jan. 20,1999, now U.S. Pat. No. 6,254,598, which is a continuation-in-part ofU.S. patent application Ser. No. 09/026,316 filed Feb. 19, 1998, nowU.S. Pat. No. 6,056,744.

FIELD OF THE INVENTION

This invention relates generally to an apparatus for the treatment ofsphincters, and more specifically to an apparatus that treats esophagealsphincters.

DESCRIPTION OF RELATED ART

Gastroesophageal reflux disease (GERD) is a common gastroesophagealdisorder in which the stomach contents are ejected into the loweresophagus due to a dysfunction of the lower esophageal sphincter (LES).These contents are highly acidic and potentially injurious to theesophagus resulting in a number of possible complications of varyingmedical severity. The reported incidence of GERD in the U.S. is as highas 10% of the population (Castell D O; Johnston B T: GastroesophagealReflux Disease: Current Strategies For Patient Management. Arch Fam Med,5(4):221–7; (1996 April)).

Acute symptoms of GERD include heartburn, pulmonary disorders and chestpain. On a chronic basis, GERD subjects the esophagus to ulcerformation, or esophagitis and may result in more severe complicationsincluding esophageal obstruction, significant blood loss and perforationof the esophagus. Severe esophageal ulcerations occur in 20–30% ofpatients over age 65. Moreover, GERD causes adenocarcinoma, or cancer ofthe esophagus, which is increasing in incidence faster than any othercancer (Reynolds J C: Influence Of Pathophysiology, Severity, And CostOn The Medical Management Of Gastro esophageal Reflux Disease. Am JHealth Syst Pharm, 53(22 Suppl 3):S5–12 (15 Nov 1996)).

One of the possible causes of GERD may be aberrant electrical signals inthe LES or cardia of the stomach. Such signals may cause a higher thannormal frequency of relaxations of the LES allowing acidic stomachcontents to be repeatedly ejected into the esophagus and cause thecomplications described above. Research has shown that unnaturalelectrical signals in the stomach and intestine can cause reflux eventsin those organs (Kelly K A, et al: Duodenal-gastric Reflux and SlowedGastric Emptying by Electrical Pacing of the Canine Duodenal PacesetterPotential. Gastroenterology. 1977 March; 72(3): 429–433). In particular,medical research has found that sites of aberrant electrical activity orelectrical foci may be responsible for those signals (Karlstrom L H, etal.: Ectopic Jejunal Pacemakers and Enterogastric Reflux after RouxGastrectomy: Effect Intestinal Pacing. Surgery. 1989 September; 106(3):486–495). Similar aberrant electrical sites in the heart which causecontractions of the heart muscle to take on life threatening patterns ordysrhythmias can be identified and treated using mapping and ablationdevices as described in U.S. Pat. No. 5,509,419. However, there is nocurrent device or associated medical procedure available for theelectrical mapping and treatment of aberrant electrical sites in the LBSand stomach as a means for treating GERD.

Current drug therapy for GERD includes histamine receptor blockers whichreduce stomach acid secretion and other drugs which may completely blockstomach acid. However, while pharmacologic agents may provide short termrelief, they do not address the underlying cause of LES dysfunction.

Invasive procedures requiring percutaneous introduction ofinstrumentation into the abdomen exist for the surgical correction ofGERD. One such procedure, Nissen fundoplication, involves constructing anew “valve” to support the LES by wrapping the gastric fundus around thelower esophagus. Although the operation has a high rate of success, itis an open abdominal procedure with the usual risks of abdominal surgeryincluding: postoperative infection, herniation at the operative site,internal hemorrhage and perforation of the esophagus or of the cardia.In fact, a recent 10 year, 344 patient study reported the morbidity ratefor this procedure to be 17% and mortality 1% (Urschel, J D:Complications Of Antireflux Surgery, Am J Surg 166(1): 68–70; (1993July)). This rate of complication drives up both the medical cost andconvalescence period for the procedure and may exclude portions ofcertain patient populations (e.g., the elderly and immuno-compromised).

Efforts to perform Nissen fundoplication by less invasive techniqueshave resulted in the development of laparoscopic Nissen fundoplication.Laparoscopic Nissen fundoplication, reported by Dallemagne et al.Surgical Laparoscopy and Endoscopy, Vol. 1, No. 3, (1991), pp. 138–43and by Hindler et al. Surgical Laparoscopy and Endoscopy, Vol. 2, No. 3,(1992), pp. 265–272, involves essentially the same steps as Nissenfundoplication with the exception that surgical manipulation isperformed through a plurality of surgical cannula introduced usingtrocars inserted at various positions in the abdomen.

Another attempt to perform fundoplication by a less invasive techniqueis reported in U.S. Pat. No. 5,088,979. In this procedure aninvagination device containing a plurality of needles is insertedtransorally into the esophagus with the needles in a retracted position.The needles are extended to engage the esophagus and fold the attachedesophagus beyond the gastroesophageal junction. A remotely operatedstapling device, introduced percutaneously through an operating channelin the stomach wall, is actuated to fasten the invaginatedgastroesophageal junction to the surrounding involuted stomach wall.

Yet another attempt to perform fundoplication by a less invasivetechnique is reported in U.S. Pat. No. 5,676,674. In this procedure,invagination is done by a jaw-like device and fastening of theinvaginated gastroesophageal junction to the fundus of the stomach isdone via a transoral approach using a remotely operated fasteningdevice, eliminating the need for an abdominal incision. However, thisprocedure is still traumatic to the LES and presents the postoperativerisks of gastroesophageal leaks, infection and foreign body reaction,the latter two sequela resulting when foreign materials such as surgicalstaples are implanted in the body.

While the methods reported above are less invasive than an open Nissenfundoplication, some still involve making an incision into the abdomenand hence the increased morbidity and mortality risks and convalescenceperiod associated with abdominal surgery. Others incur the increasedrisk of infection associated with placing foreign materials into thebody. All involve trauma to the LES and the risk of leaks developing atthe newly created gastroesophageal junction.

Besides the LES, there are other sphincters in the body which if notfunctionally properly can cause disease states or otherwise adverselyaffect the lifestyle of the patient. Reduced muscle tone or otherwiseaberrant relaxation of sphincters can result in a laxity of tightnessdisease states including, but not limited to, urinary incontinence.

There is a need to provide an apparatus to treat a sphincter and reducea frequency of sphincter relaxation. Another need exists for anapparatus to create controlled cell necrosis in a sphincter tissueunderlying a sphincter mucosal layer. Yet another need exists for anapparatus to create cell necrosis in a sphincter and minimize injury toa mucosal layer of the sphincter. There is another need for an apparatusto controllably produce lesions in a sphincter without creating apermanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure. Still a further need exists foran apparatus to create a tightening of a sphincter without permanentlydamaging anatomical structures near the sphincter. There is stillanother need for an apparatus to create cell necrosis in a loweresophageal sphincter to reduce a frequency of reflux of stomach contentsinto an esophagus.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide anapparatus to treat a sphincter and reduce a frequency of sphincterrelaxation.

Another object of the invention is to provide an apparatus to createcontrolled cell necrosis in a sphincter tissue underlying a sphinctermucosal layer.

Yet another object of the invention is to provide an apparatus to createcell necrosis in a sphincter and minimize injury to a mucosal layer ofthe sphincter.

A further object of the invention is to provide an apparatus tocontrollably produce a lesion in a sphincter without creating apermanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure.

Still another object of the invention is to provide an apparatus tocreate a tightening of a sphincter without permanently damaginganatomical structures near the sphincter.

Another object of the invention is to provide an apparatus to createcell necrosis in a lower esophageal sphincter to reduce a frequency ofreflux of stomach contents into an esophagus.

Yet another object of the invention is to provide an apparatus to reducethe frequency and severity of gastroesophageal reflux events.

These and other objects of the invention are provided in a sphinctertreatment apparatus. The apparatus includes an elongated member withlumen and a basket assembly with first and second arms. The basketassembly is coupled to the elongated member and has deployed andnon-deployed configurations. An inflatable member is coupled to theelongated member and positioned in an interior of state, the inflatablemember expands the basket assembly to its deployed configuration. Afirst energy delivery device is positionable in the first arm andadvanceable from the first arm to a selected treatment site. A secondenergy delivery device is positionable in the second arm and advanceablefrom the second arm to a selected treatment site the basket assembly.The inflatable member has deployed and non-deployed states and iscoupled to the elongated member lumen. In the deployed state, theinflatable member expands the basket assembly to its deployedconfiguration. A first energy delivery device is positionable in thefirst arm and advanceable from the first arm to a selected treatmentsite. A second energy delivery device is positionable in the second armand advanceable from the second arm to a selected treatment site.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrated lateral view of the upper GI tract includingthe esophagus and lower esophageal sphincter and the positioning of thesphincter treatment apparatus of the present invention in the loweresophageal sphincter.

FIG. 2 a is a cross-sectional view of one embodiment of the presentinvention illustrating the inflatable member, the delivery of energyfrom the basket assembly and advancement of an elongated medical devicethrough a lumen of the elongated member.

FIG. 2 b is a perspective view of an embodiment of the inventionillustrating the use of lumens and tubes in the basket arms.

FIG. 2 c is a perspective view illustrating an embodiment of theinvention where the energy delivery devices are deployed in multi-levelgeometries.

FIG. 2 d is a cross-sectional view illustrating the attachment of energydelivery devices to the basket arms and balloon.

FIG. 2 e is a cross-sectional view illustrating an energy deliverydevice comprising a conductive coating on or in the balloon.

FIG. 2 f is a cross-sectional view illustrating the use of needles as REenergy delivery devices, including the use of hollow and insulatedneedles.

FIG. 2 g is a cross-sectional view illustrating the use of a drugdelivery device and medicament coupled to the apparatus of FIG. 2A.

FIG. 3 is a cross-sectional view illustrating the creation of lesions ina sphincter using the apparatus of FIG. 2A.

FIG. 4 is a cross-sectional view illustrating the use of a cooling mediaand its introduction via the basket arms or energy delivery devices.

FIG. 5 a is a cross-sectional view of an embodiment of the apparatuswhere the balloon has a deployed, non-circular, cross-sectional geometrythat provides for the creation of axial flow channels adjacent to anexterior of the sphincter.

FIG. 5 b is a cross-sectional view of an embodiment where the balloonhas a pear shape.

FIGS. 5 c and 5 d are cross-sectional views of embodiments of theinvention where the balloon has a Cassini oval dogbone and oval shape.

FIG. 6 is a cross-sectional view illustrates deployment of a balloonwhich has an elongated, substantially non-tapered geometry.

FIG. 7 is a cross-sectional view of the apparatus of FIG. 2Aillustrating the coupling of an energy delivery device advancement andretraction member.

FIG. 8 is a cross-sectional view of an arm of the apparatus of FIG. 2Awhere all of the energy delivery devices positioned in the arm areadvanced and retracted by a single advancement member.

FIG. 9 is a cross-sectional view illustrating an embodiment of theinvention having an insulated lumen that carries individual power wiresthat are coupled to separate energy delivery devices.

FIGS. 10 a and 10 b are cross-sectional views illustrating the use ofover indexing with an advancement mechanism to reduce the occurrence oftenting during needle insertion into sphincter wall tissue.

FIG. 10 c is a cross-sectional view of an embodiment of the advancementmechanism utilizing mechanical stops and springs.

FIG. 11 is a flow chart illustrating a sphincter treatment method usingthe apparatus of the present invention.

FIG. 12 is a cross-sectional view of a multi-channel RF generator usefulwith the apparatus of FIG. 2A.

FIG. 13 is a cross-sectional view of an RF generator that sequentiallydelivers energy to distinct RF electrodes.

FIG. 14 depicts a block diagram of a feed back control system that canbe used with the sphincter treatment apparatus of the present invention.

FIG. 15 depicts a block diagram of an analog amplifier, analogmultiplexer and microprocessor used with the feedback control system ofFIG. 14.

FIG. 16 depicts a block diagram of the operations performed in thefeedback control system of FIG. 14.

DETAILED DESCRIPTION

Referring now to FIG. 1, one embodiment of sphincter treatment apparatus10 is illustrated. Apparatus 10 delivers energy to a treatment site 12to produce lesions 14 in a sphincter 16, such as the lower esophagealsphincter (LES) having a wall 17 and mucosal layers 17′. Apparatus 10includes a flexible elongate shaft 18 which can be an introducer,cannula, catheter and the like.

As illustrated in FIG. 2 a, shaft 18 is coupled to a basket assembly 20.Basket assembly 20 is made of a plurality of arms 21. A plurality ofenergy delivery devices 22 are positioned and advanced from arms 21 intodifferent circumferential regions of tissue site 12 or other treatmentsite within the sphincter wall 17 or adjacent anatomical structure.Energy delivery devices 22 are positioned, advanceable and retractableto and from basket assembly 20. Energy delivery devices 22 arepositioned a desired depth in a sphincter wall 17 or adjoininganatomical structure. Energy delivery devices 22 are configured to becoupled to an energy source 24. An inflatable or expandable member 25 isalso coupled to shaft 18 and is preferably an inflatable balloon wellknown in the art. Balloon 25 is positioned within the interior of basketassembly 20.

Shaft 18 has a proximal and distal end 18′ and 18″ and has sufficientlength to position expandable basket assembly 20 in the LES and/orstomach including the cardia using a transoral approach. Typical lengthsfor shaft 18 include, but are not limited to, a range of 40–180 cms. Invarious embodiments, shaft 18 is flexible, articulated and steerable andcan contain fiber optics (including illumination and imaging fibers),fluid and gas paths, and sensor and electronic cabling. In oneembodiment, shaft 18 can be a multi-lumen catheter, as is well known tothose skilled in the art. Shaft 18 cam also be coupled to a proximalhandle 31, which in various embodiments can include handle ports 31′ forballoon inflation, and the delivery of cooling and other fluidsdescribed herein. Ports 31′ can include but are not limited to valves(one-way or two-way), luer fittings and other adaptors and medicalfittings known in the art.

Basket assembly 20 is configured to be positionable in a sphincter 16such as the LES or adjacent anatomical structure, such as the cardia ofthe stomach. Basket assembly 20 has a central longitudinal axis 20′ andis moveable between contracted and expanded positions (also callednon-deployed and deployed configurations) substantially there along. Invarious embodiments, this can be accomplished without a balloon using apullwire mechanism (not shown) which can include a ratchet mechanism forlocking the pull wire in given position. At least portions of apparatus10 may be sufficiently radiopaque in order to be visible underfluoroscopy and/or sufficiently echogenic to be visible underultrasonography. Also as will be discussed herein, apparatus 10 caninclude visualization capability including, but not limited to, aviewing scope, an expanded eyepiece, fiber optics, video imaging and thelike. Such viewing means may be delivered through a central lumen 19within elongated shaft 18 or within or alongside basket assembly 20. Invarious embodiments, elongated shaft 18 may have multiple lumens 19which can be configured for the advancement of various elongated medicaldevices 23 to a treatment site 12 or other area in the body. Elongatedmedical devices 23 can include guidewires, drug delivery catheters,manometry catheters, pH monitoring catheters, endoscopes, viewing scopesand the like. Lumens 19 can also be configured for the delivery ofliquids (including cooling liquids), gases and drugs or medicaments 13to a treatment site 12 or other area of the body. In one embodimentlumen 19 can be configured as an inflation lumen described herein toinflate inflatable member 25 using a liquid or gaseous inflation media.

Referring now to FIG. 2 b, arms 21 can have one or more channels orlumens 21′ or may comprise multiple tubes 21″ to allow multiplefunctions to be performed at each arm such as needle deployment and thedelivery of cooling or electrolytic fluids. Also, arms 21 may form avariety of geometric shapes including, but not limited to, curved,rectangular, trapezoidal and triangular. Arms 21 can also have anynumber of different cross sectional geometries including, but notlimited to, circular, rectangular and crescent-shaped. In oneembodiment, arms 21 are of a sufficient number, such as two or more, andwith adequate spring force (0.01 to 0.5 lbs. force) to collectivelyexert enough force on the sphincter wall 17 to open and efface the foldsof sphincter 16. Arms 21 can be made of a variety of different materialsincluding but not limited to, spring steel, stainless steel,superelastic shape memory metals such as nitinol, un-reinforced plastictubing, or wire reinforced plastic tubing as is well known to thoseskilled in the art. Arms 21 can also have an outwardly bowed shapedmemory for expanding basket assembly 20 into engagement with thesphincter wall, with the amount of bowing or camber 20″ beingselectable. Aims 21 may be preshaped at time of manufacture or shaped bythe physician.

In another embodiment, arms 21 may have an external layer of thetexturized material that has sufficient friction to at least partiallyimmobilize the area of sphincter wall near and around that contacted byan arm 21. Suitable materials for the texturized material includeknitted Dacron® and Dacron velour.

In one embodiment, illustrated in FIG. 2 c, energy delivery devices 22are deployed in multi-level geometries. As shown, first, second andthird levels of energy delivery devices 22′, 22″ and 22′″ are deployed.The energy delivery devices 22 of each level define a plane ofdeployment 33 which can include first second and third deployment planes33′, 33″ and 33′″. Each plane of deployment for the differentmulti-levels can be parallel. In various embodiments, first, second andthird levels of energy delivery devices 22′, 22″ and 22′″ are deployedsimultaneously or alternatively sequentially.

Turning now to a discussion of energy delivery, suitable energy sources24 and energy delivery devices 22 that can be employed in one or moreembodiments of the invention include: (i) a radio-frequency (RF) sourcecoupled to an RF electrode, (ii) a coherent source of light coupled toan optical fiber, (iii) an incoherent light source coupled to an opticalfiber, (iv) a heated fluid coupled to a catheter with a closed channelconfigured to receive the heated fluid, (v) a heated fluid coupled to acatheter with an open channel configured to receive the heated fluid,(vi) a cooled fluid coupled to a catheter with a closed channelconfigured to receive the cooled fluid, (vii) a cooled fluid coupled toa catheter with an open channel configured to receive the cooled fluid,(viii) a cryogenic fluid, (ix) a resistive heating source coupled to aheating element positioned either on the arms to heat tissue directly orwithin the balloon to heat the inflation medium, (x) a microwave sourceproviding energy from 915 MHz to 2.45 GHz and coupled to a microwaveantenna, or (xi) an ultrasound power source coupled to an ultrasoundemitter, wherein the ultrasound power source produces energy in therange of 300 KHZ to 3 GHz. For ease of discussion for the remainder ofthis specification, the power source utilized is an RF source and energydelivery device 22 is one or more RF electrodes 22. However, all of theother herein mentioned energy sources and energy delivery devices areequally applicable to sphincter treatment apparatus 10.

For the case of RF energy, RF electrode 22 may be operated in eitherbipolar or monopolar mode with a ground pad electrode. In a monopolarmode of delivering RF energy, a single electrode 22 is used incombination with an indifferent electrode patch that is applied to thebody to form the other electrical contact and complete an electricalcircuit. Bipolar operation is possible when two or more electrodes 22are used. Electrodes 22 can be attached to an electrode delivery member(describe herein) by the use of soldering methods which are well knownto those skilled in the art. Suitable solders include Megabond Soldersupplied by the Megatrode Corporation (Milwaukee, Wis.). Other joiningmethods include, but are not limited to, welding and adhesive bonding(including the use of conductive adhesives known in the art). In variousembodiments, the electrode to delivery member joint can be conductive(for the case where electrodes 22 are activated simultaneously) ornonconductive (for the case where electrodes 22 are activatedindividually). In the latter case, electrodes are attached to individualconductors and are electrically isolated from each other (e.g. otherelectrodes).

Referring now to FIGS. 2 d and 2 e, in other embodiments, electrodes 22can be attached to arms 21, or balloon 25 using adhesive bonding orother joining methods known in the art. In one embodiment all or aportion of electrodes 22 can integral to or otherwise built into arms21. This can be accomplished using a variety of plastic processingmethods known in the art including, the use of heated capture tubesand/or heated collets or notching fixtures. In one embodiment,electrodes 22 can be substantially flush with the surface of arms 21.Electrodes 22 can also be attached to the exterior surface 25′ ofballoon 25. In one embodiment shown in FIG. 2 e, electrode 22 maycomprise a conductive coating or layer 25″ that is applied to all or aportion of the or exterior 25′ or interior 25″ surface of balloon 25 oris otherwise incorporated/embedded into the wall of balloon 25. Coating25′″ may include conductive polymers or metals (e.g. gold, platinum,etc.) and may applied using, sputtering, spraying or electro/chemicaldeposition techniques known in the art. In one embodiment, conductivecoating 25′″ can be applied to discrete areas on the exterior surface25′ of balloon 25 using masking and electro/chemical depositiontechniques known in the art.

RF electrodes 22 can have a variety of shapes and sizes. Possible shapesinclude, but are not limited to, circular, rectangular, conical andpyramidal. Electrode surfaces can be smooth or textured and concave orconvex. The conductive surface area of electrode 22 can range from 0.1cm2 to 100 cm2. It will be appreciated that other geometries and surfaceareas may be equally suitable.

Referring now to FIG. 2 f in one embodiment, RF electrodes 22 can be inthe shape of needles and of sufficient sharpness and length to penetrateinto the smooth muscle of the esophageal wall, sphincter 16 or otheranatomical structure. An insulation sleeve 27 can be positioned at anexterior of each RF electrode 22. The use of insulation sleeve 27creates an insulated segment 27′ of RF electrode 22 and providesprotection of the mucosal layer 17′ of sphincter 16. For purposes ofthis disclosure, an insulator or insulation layer is a barrier to eitherthermal, RF or electrical energy flow. The insulated segment of RFelectrode 22 is of sufficient length to extend into the sphincter wall17 and minimize transmission of RF energy to a protected site 12′ nearor adjacent to insulated segment 27′. Typical lengths for insulatedsegment 27′ include, but are not limited to, 1–8 mms, with preferredembodiments of 2, 5 and 8 mms. Typical lengths for the uninsulatedportion or segment 27″ of electrode 22 include 2 to 6 mms, withpreferred embodiments of 3, 4 and 5 mms.

Suitable materials for RF electrodes 22 include, but are not limited to,304 stainless steel and other stainless steels known to those skilled inthe art. Suitable materials for insulation sleeve 27 include, but arenot limited to, polyimides and parylene; and in a preferred embodiment,PET (polyethylene terephthalate).

Referring back to FIG. 2 a, balloon 25 can be coupled to and inflated byan inflation lumen 26 (which can also be lumen 19) using gas or liquidas is known in the art. This results in balloon 25 going from annon-deployed to a deployed state. Inflation lumen 26 can be coupled tohandle port 31′ which can be a one-way valve known in the art. All or aportion of balloon 25 can be made of a non compliant material (as isknown in the art) in order to achieve a predictable fixed balloondiameter. In various embodiments, such non compliant materials includePET, irradiated polyethylene, polyurethane and others known in the art.In alternative embodiments, balloon 25 can be configured to have anadjustable diameter by constructing all or a portion of balloon 25 fromcompliant materials. Such compliant materials include latex, silicone,C-flex and other thermoplastics and elastomers known in the art. All ora portion of balloon 25 may be made of a textured material, or have atexturized layer that when engaged with a sphincter wall 17 providessufficient friction to at least partially immobilize the surface of thesphincter wall. Suitable materials for the texturized layer includeknitted Dacron® and Dacron velour.

Referring now to FIG. 2 g, apparatus 10 can also be configured to becoupled to a medical device 23′ including a drug delivery device, 23′.In various embodiments, drug delivery device 23′ can include an infusionpump, syringe (manual or motorized) IV bag with a pressure clamp orother drug delivery device known in the art. Drug delivery device 23′can also be coupled to medicament 13 and or medicament reservoir 13′containing medicament 13.

Referring now to FIG. 3, energy delivery devices 22 are advanced intosphincter wall 17 a sufficient distance to create lesions 14 whilepreserving sphincter mucosal layer 17′. In one embodiment, lesions 14are created circumferentially and equally distanced in order to createan even tightening of sphincter 16. In another embodiment, lesions arecreated that are about 1 mm below the surface of sphincter wall mucosallayer 17′ and extend to a depth of about 4 mm within sphincter wall 17.

Referring now FIG. 4, a fluidic media 35, including but not limited to,a cooling media 35, can be introduced through arms 21. Cooling media 35is introducible through ports 21′″ or apertures 21′″ from which energydelivery devices 22 are advanced or through distinct and separateapertures 21′″. Arms 21 can be fluidically coupled to cooling media 35and/or a cooling media reservoir 35′ via arm lumens 21′. Other suitablefluidic media 35 include, but are not limited to, sterile water, saline,anti-infective agents, echogenic media, steroids, local anesthetics andthe like. The use of cooling preserves the mucosal layers 17′ ofsphincter 16 and protects, or otherwise reduces the degree of celldamage in the vicinity of lesion 14.

Similarly, it may also be desirable to cool all or a portion of RFelectrode 22. The rapid delivery of heat through RF electrodes 22 mayresult in the build up of charred biological matter on RF electrodes 22(from contact with tissue and fluids e.g., blood) that impedes the flowof both thermal and electrical energy from RF electrodes 22 to adjacenttissue and causes an electrical impedance rise beyond a cutoff value seton RF energy source 24. A similar situation may result from thedesiccation of tissue adjacent to RF electrodes 22. Cooling of RFelectrodes 22 can be accomplished by the use of cooling media 35.

Additionally, electrodes 22 can be hollow and used to introduceelectrolytic solutions into sphincter 16 and sphincter wall 17 throughthe use of ports 21′″ disposed on electrodes 22 that are fluidicallycoupled to cooling media 35 and/or cooling media reservoir 35′. Suitableelectrolytic solutions include saline; and solutions of calcium salts,potassium salts, and the like. Electrolytic solutions enhance theelectrical conductivity of the targeted tissue at the treatment site 12.When a highly conductive fluid such as an electrolytic solution isinfused into tissue the electrical resistance of the infused tissue isreduced, in turn, increasing the electrical conductivity of the infusedtissue. As a result, there is little tendency for tissue surrounding RFelectrode 22 to desiccate (a condition described herein that increasesthe electrical resistance of tissue) resulting in a large increase inthe capacity of the tissue to carry RF energy.

One or more sensors 29 may be positioned adjacent to or on RF electrode22 for sensing the temperature of sphincter tissue at treatment site 12.More specifically, sensors 29 permit accurate determination of thesurface temperature and/or interior temperature of sphincter 16. Thisinformation can be used to regulate both the delivery of energy andcooling media 35 to sphincter 16. In various embodiments, sensors 29 canbe positioned at any position on balloon 25, basket assembly 20 or at anRF electrode 22. Suitable sensors that may be used include but are notlimited to, thermocouples, fiber optics, resistive wires, thermocoupleIR detectors, and the like. Suitable thermocouples include T type withcopper constantene, J type, F type and K types as are well known thoseskilled in the art.

As illustrated in FIGS. 5 a–5 d, balloon 25 can have a variety ofdifferent deployed geometric configurations. Such configurationsinclude, but are not limited to, spherical, football-shaped,cylindrical, channeled dog bone, oval and pear shapes. In the embodimentillustrated in FIG. 5 a, balloon 25 has a non-circular cross-sectionwhich creates axial channels 30 between an exterior surface 25′ ofballoon 25 and sphincter 16. Axial channels 30 provide for the flow (inboth proximal and distal directions) of any suitable fluid or media,such as a cooling media 35, at the interior surface of sphincter wall17. In the embodiment illustrated in FIG. 5 b, balloon 25 can be atleast partially pear-shaped to approximately match the shape of thecardia of the stomach. In embodiments illustrated in FIGS. 5 c and 5 d,balloon 25 can have a Cassini oval shape, including embodiments wherethe Cassini oval has a dog bone (FIG. 5 c) shape or oval shape (FIG. 5d). The dog bone shape facilitates maintaining the position of balloon25 in a sphincter such as the LES or other stricture.

Another geometric configuration of balloon 25 is illustrated in FIG. 6.In this embodiment, balloon 25 has a substantially uniform interfacesurface 39 with sphincter wall 17. This uniformity providessubstantially even contact between arms 21 and sphincter wall 17 inorder to create uniform lesion 14 creation.

Referring now to FIG. 7, an electrode advancement and retraction member32 (also called an electrode delivery member) is coupled to RFelectrodes 22. In various embodiments electrode advancement andretraction member 32 can be an insulated wire, an insulated guide wire,a plastic-coated stainless steel hypotube with internal wiring or aplastic catheter with internal wiring, all of which are known to thoseskilled in the art. Retraction member 32 can also have a preshaped curvethat can be directed by torquing member 32 or can be activelydeflectable via the use of a pullwire or other mechanisms known in theart. Lumen 19 and retraction member 32 can be configured such thatretraction member 32 is advanceable within lumen 19.

In one embodiment, all RF electrodes 22 can be coupled to the sameelectrode advancement and retraction member 32. Alternatively, variousnumbers and groups of RF electrodes can be coupled to differentelectrode advancement and retraction members 32. In the embodimentillustrated in FIG. 8, all HF electrodes 22 in an arm 21 are coupled tothe same electrode advancement and retraction member 32 and as such, canbe advanced into sphincter 16 simultaneously. In this and relatedembodiments, retraction member 32 can be employed so as to producemultiple lesions 14 in the sphincter wall 17 while maintaining apparatus10, in a substantially stationary position within sphincter 16. Theconfiguration and use of retraction member 32 in this manner providesthe advantage of reduced procedure time and a reduced likelihood of anytrauma to the esophagus and surrounding tissue due to a reduced need tomanipulate the apparatus within the esophagus.

Referring now to FIG. 9, each RF electrode 22 can be coupled to aseparate power wire 34 that is coupled to energy source 24. This permitsRF electrodes to deliver energy non-simultaneously and offers thefollowing advantages: i) individually tailored power delivery for eachelectrode, ii) individually temperature control for each electrode, iii)ability to compensate for differences in local tissue characteristics(e.g. electrical impedance, morphology, etc.) adjacent each electrode orvariations in electrode penetration depth for the use of multipleelectrodes, iv) more precise control of lesion location and size, v)generation of eccentric lesions or otherwise varying lesion locationsand sizes, and vi) reduced procedure time. In alternative embodiments,energy delivery by multiple electrodes can be performed simultaneouslythrough separate RF electrodes by utilizing a multichannel RF generatoror by multiplexing the delivery of RF energy from a single RF energysource 24 to multiple RF electrodes 22 using multiplexing circuitry wellknown in the art. In still other embodiments, RF energy can be deliveredsequentially to different electrode using a simple switch box known inthe art.

Also when the energy source is RF, energy source 24, which will now bereferred to as RF energy source 24, may have multiple channels,delivering separately modulated power to each RF electrode 22. Thisconfiguration reduces preferential heating that occurs when more energyis delivered to a zone of greater conductivity and less heating occursaround RF electrodes 22 which are placed into less conductive tissue. Ifthe level of tissue hydration or the blood infusion rate in the tissueis uniform, a single channel RF energy source 24 may be used to providepower for generation of lesions 14 relatively uniform in size.

During introduction of apparatus 10, basket assembly 20 is in acontracted or non-deployed state. Once apparatus 10 is properlypositioned at the treatment site 12, balloon 25 is inflated, basketassembly 20 is deployed (expanded) and HF electrodes 22 are thenintroduced into sphincter wall 17. The depth of needle penetration isselectable from a range of about 0.5 to 5 mms and can be accomplished byan indexed movable fitting coupled to shaft 18.

Referring now to FIGS. 10 a and 10 b, in another embodiment electrodesor needles 22 can be initially over-indexed to puncture throughsphincter wall tissue to a first position and then retracted to a secondor detent position where the needle tip is well within a desiredpenetration depth range in the esophageal wall tissue (e.g. 1–4 mms) forsafe and effective tissue ablation of the desired treatment site 12.Such a configuration has the advantage of reducing or eliminating theoccurrence of “tenting’ of esophageal and/or sphincter tissue that mayoccur during electrode needle penetration. In these and relatedembodiments, the advancement of electrode 22 can be controlled by theuse of an electrode advancement mechanism 37 or fixture 37. As shown inFIGS. 10 a and 10 b, advancement mechanism 37 can include a ratchetmechanism or indexing mechanism, and the like. Alternatively as shown inFIG. 10 c, mechanism 37 can include the use of a combination ofmechanical stops and springs disposed in arm 21. In still otherembodiments, mechanism 37 can include a combination one or more of thefollowing: springs, stops, a ratchet mechanism or indexing mechanism. Invarious embodiments, advancement mechanism 37 can also be positioned atthe proximal end 18′ of the elongated shaft 18, on or within handpiece31 or within arm 21.

RF energy flowing through sphincter or other tissue causes heating ofthe tissue due to absorption of the RF energy by the tissue and ohmicheating due to electrical resistance of the tissue. This heating cancause injury to the affected cells which can be substantial enough tocause cell death, a phenomenon also known as cell necrosis. For ease ofdiscussion for the remainder of this application, cell injury willinclude all cellular effects resulting from the delivery of energy fromRF electrode 22 up to, and including, cell necrosis. Cell injury can beaccomplished as a relatively simple medical procedure with localanesthesia. In one embodiment, cell injury proceeds to a depth ofapproximately 1–4 mms from the surface of the mucosal layer 17′ ofsphincter 16 or that of an adjoining anatomical structure.

FIG. 11 is a flow chart illustrating one embodiment of the procedure forusing apparatus 10. In this embodiment, apparatus 10 is first introducedinto the esophagus under local anesthesia. Apparatus 10 can beintroduced into the esophagus by itself or through a lumen in anendoscope (not shown), such as disclosed in U.S. Pat. Nos. 5,448,990 and5,275,608, both incorporated herein by reference, or similar esophagealaccess device known to those skilled in the art. Basket assembly 20 isexpanded. Once introduced, basket assembly 20 is deployed by inflationof balloon 25 or other means. This serves to temporarily dilate the LESor sufficiently to efface a portion of or all of the folds of the LES.In an alternative embodiment, esophageal dilation and subsequent LESfold effacement can be accomplished by insufflation of the esophagus (aknown technique) using gas introduced into the esophagus. Once treatmentis completed, basket assembly 20 is returned to its predeployed orcontracted state and apparatus 10 is withdrawn from the esophagus. Thisresults in the LES returning to approximately its pretreatment state anddiameter. It will be appreciated that the above procedure is applicablein whole or part to the treatment of other sphincters in the body.

The diagnostic phase of the procedure can be performed using a varietyof diagnostic methods, including, but not limited to, the following: (i)visualization of the interior surface of the esophagus via an endoscopeor other viewing apparatus inserted into the esophagus, (ii)visualization of the interior morphology of the esophageal wall usingultrasonography to establish a baseline morphology for the tissue to betreated, (iii) impedance measurement to determine the electricalconductivity between the esophageal mucosal layers 17′ and apparatus 10,(iv) esophageal pressure measurement to determine location of the LESusing esophageal manometry methods which may include the use of amanometry catheter and measurement system such as that sold by MedtronicSynectics (Stockholm, Sweden), (v) measurement and surface mapping ofthe electropotential of the LES during varying time periods which mayinclude such physiological events as depolarization, contraction andrepolarization of LES smooth muscle tissue. This latter technique isdone to determine target treatment sites 12 in the LES or adjoininganatomical structures.

In the treatment phase of the procedure, the delivery of energy totreatment site 12 can be conducted under feedback control, manually orby a combination of both. Feedback control (described herein) enablesapparatus 10 to be positioned and retained in the esophagus duringtreatment with minimal attention by the physician. RF electrodes 22 canbe multiplexed in order to treat the entire targeted treatment site 12or only a portion thereof. Feedback can be included and is achieved bythe use of one or more of the following methods: (i) visualization, (ii)impedance measurement, (iii) ultrasonography, (iv) temperaturemeasurement; and, (v) sphincter contractile force (e.g. pressure)measurement via manometry. The feedback mechanism permits the selectedon-off switching of different RF electrodes 22 in a desired pattern,which can be sequential from one RF electrode 22 to an adjacent RFelectrode 22, or can jump around between non-adjacent RF electrodes 22.Individual RF electrodes 22 can be multiplexed and volumetricallycontrolled by a controller.

The area and magnitude of cell injury in the LES or sphincter 16 canvary. However, it is desirable to deliver sufficient energy to thetargeted treatment site 12 to be able to achieve tissue temperatures inthe range of 55–95° C. and produce lesions 14 at depths ranging from 1–4mms from the interior surface of the LES or sphincter wall 17. Typicalenergies delivered to the sphincter wall 17 include, but are not limitedto, a range between 100 and 50,000 joules per RF electrode 22. It isalso desirable to deliver sufficient energy such that the resultinglesions 14 have a sufficient magnitude and area of cell injury to causean infiltration of lesion 14 by fibroblasts, myofibroblasts, macrophagesand other cells involved in the tissue healing process. These cellscause a contraction of tissue around lesion 14, decreasing its volumeand/or altering the biomechanical properties at lesion 14 so as toresult in a tightening of LES or sphincter 16.

From a diagnostic standpoint, it is desirable to image the interiorsurface and wall 17 of the LES or other sphincter 16, including the sizeand position of created lesions 14. A map of these lesions 14 caninputted to a controller and used to direct the delivery of energy tothe treatment site. This can be accomplished through the use ofultrasonography (a known procedure) which involves the use of anultrasound energy source coupled to one or more ultrasound transducersthat can be positioned on balloon 25 or basket assembly 20. An output isassociated with the ultrasound energy source.

It is desirable that lesions 14 be predominantly located in the smoothmuscle layer of selected sphincter 16 at the depths ranging from 1 to 4mms from the interior surface of sphincter wall 17. However, lesions 14can vary both in number and position within sphincter 16. It may bedesirable to produce a pattern of multiple lesions 14 within thesphincter smooth muscle tissue in order to obtain a selected degree oftightening of the LES or other sphincter 16. Typical lesion patternsinclude, but are not limited to, (i) a concentric circle of lesions 14formed at different levels in the smooth muscle layer evenly spacedalong the radial axis of sphincter 16, (ii) a wavy or folded circle oflesions 14 at varying depths in the smooth muscle layer evenly spacedalong the radial axis of sphincter 16, (iii) lesions 14 randomlydistributed at varying depths in the smooth muscle, but evenly spaced ina radial direction; and, (iv) an eccentric pattern of lesions 14 in oneor more radial locations in the smooth muscle wall. Accordingly, thedepth of RF and thermal energy penetration sphincter 16 is controlledand selectable. The selective application of energy to sphincter 16 maybe the even penetration of RF energy to the entire targeted treatmentsite 12, a portion of it, or applying different amounts of RF energy todifferent sites depending on the condition of sphincter 16. If desired,the area of cell injury can be substantially the same for everytreatment event.

Referring now to FIG. 12, RF energy source 24 can include independent RFchannels 24′ that operate in parallel and are coupled to different RFelectrodes 22. As illustrated in FIG. 13, RF energy source 24 can beconfigured (using circuitry known in the art such as a multiplexingcircuit) to deliver energy to multiple RF electrodes 22 in atime-sharing fashion. This permits the delivery of RF energy toindividual RF electrodes 22 for a selected period of time to each RFelectrode 22 in a sequential manner.

In one embodiment, apparatus 10 is coupled to an open or closed loopfeedback system. Referring now to FIG. 14, an open or closed loopfeedback system couples sensor 129 to energy source 124. In thisembodiment, RF electrode 122 is one or more RF electrodes 122.

The temperature of the sphincter wall tissue, or of RF electrode 122 ismonitored, and the output power of energy source 124 adjustedaccordingly. The physician can, if desired, override the closed or openloop system. A microprocessor 136 can be included and incorporated inthe closed or open loop system to switch power on and off, as well asmodulate the power. The closed loop system utilizes microprocessor 136to serve as a controller 138, monitor the temperature, adjust the RFpower, analyze the result, refeed the result, and then modulate thepower.

With the use of sensor 129 and the feedback control system a tissueadjacent to RF electrode 122 can be maintained at a desired temperaturefor a selected period of time without causing a shut down of the powercircuit to RF electrode 122 due to the development of excessiveelectrical impedance at RF electrode 122 or adjacent tissue as isdiscussed herein. Each RF electrode 122 is connected to resources whichgenerate an independent output. The output maintains a selected energyat RF electrode 122 for a selected length of time.

Current delivered through RF electrode 122 is measured by current sensor140. Voltage is measured by voltage sensor 142. Impedance and power arethen calculated at power and impedance calculation device 144. Thesevalues can then be displayed at user a interface and display 146.Signals representative of power and impedance values are received bycontroller 138.

A control signal is generated by controller 138 that is proportional tothe difference between an actual measured value (e.g. an analog ordigital signal indicative of temperature, power, etc.) and a desiredvalue. The control signal is used by power circuits 148 to adjust thepower output in an appropriate amount in order to maintain the desiredpower delivered at respective RF electrodes 122.

In a similar manner, temperatures detected at sensor 129 providefeedback for maintaining a selected power. The temperature at sensor 129is used as a safety means to interrupt the delivery of energy whenmaximum pre-set temperatures are exceeded. The actual temperatures aremeasured at temperature measurement device 150, and the temperatures aredisplayed at user interface and display 146. A control signal isgenerated by controller 138 that is proportional to the differencebetween an actual measured temperature and a desired temperature. Thecontrol signal is used by power circuits 148 to adjust the power outputin an appropriate amount in order to maintain the desired temperaturedelivered at the sensor 129. A multiplexer can be included to measurecurrent, voltage and temperature, at the sensor 129, and energy can bedelivered to RF electrode 122 in monopolar or bipolar fashion.

Controller 138 can be a digital or analog controller, or a computer withsoftware. When controller 138 is a computer it can include a CPU coupledthrough a system bus. This system can include a keyboard, a disk drive,or other non-volatile memory systems, a display, and other peripherals,as are known in the art. Also coupled to the bus is a program memory anda data memory.

User interface and display 146 includes operator controls and a display.Controller 138 can be coupled to imaging systems including, but notlimited to, ultrasound, CT scanners, X-ray, MRI, mammographic X-ray andthe like. Further, direct visualization and tactile imaging can also beutilized.

The output of current sensor 140 and voltage sensor 142 are used bycontroller 138 to maintain a selected power level at RF electrode 122.The amount of RF energy delivered controls the amount of power. Aprofile of the power delivered to electrode 122 can be incorporated incontroller 138 and a preset amount of energy to be delivered may also beprofiled.

Circuitry, software and feedback to controller 138 result in processcontrol, the maintenance of the selected power setting which isindependent of changes in voltage or current, and is used to change thefollowing process variables: (i) the selected power setting, (ii) theduty cycle (e.g., on-off time), (iii) bipolar or monopolar energydelivery; and, (iv) fluid delivery, including flow rate and pressure.These process variables are controlled and varied, while maintaining thedesired delivery of power independent of changes in voltage or current,based on temperatures monitored at sensor 129.

Referring now to FIG. 15, current sensor 140 and voltage sensor 142 areconnected to the input of an analog amplifier 152. Analog amplifier 152can be a conventional differential amplifier circuit for use with sensor129. The output of analog amplifier 152 is sequentially connected by ananalog multiplexer 156 to the input of A/D converter 158. The output ofanalog amplifier 152 is a voltage which represents the respective sensedtemperatures. Digitized amplifier output voltages are supplied by A/Dconverter 158 to microprocessor 136. Microprocessor 136 may be a type68HCII available from Motorola or a Pentium® type available from theIntel® Corporation. However, it will be appreciated that any suitablemicroprocessor or general purpose digital or analog computer can be usedto calculate impedance or temperature.

Microprocessor 136 sequentially receives and stores digitalrepresentations of impedance and temperature. Each digital valuereceived by microprocessor 136 corresponds to different temperatures andimpedances.

Calculated power and impedance values can be indicated on user interfaceand display 146. Alternatively, or in addition to the numericalindication of power or impedance, calculated impedance and power valuescan be compared by microprocessor 136 to power and impedance limits.When the values exceed predetermined power or impedance values, awarning can be given on user interface and display 146, andadditionally, the delivery of RF energy can be reduced, modified orinterrupted. A control signal from microprocessor 136 can modify thepower level supplied by energy source 124.

FIG. 16 illustrates a block diagram of a temperature and impedancefeedback system that can be used to control the delivery of energy totissue site 112 by energy source 124 and the delivery of coolingsolution to RF electrode 122 and/or tissue site 112 by flow regulator160. Energy is delivered to RF electrode 122 by energy source 124, andapplied to tissue site 112. A monitor 162 ascertains tissue impedance,based on the energy delivered to tissue, and compares the measuredimpedance value to a set value. If the measured impedance exceeds theset value, a disabling signal 164 is transmitted to energy source 124,ceasing further delivery of energy to RF electrode 122. If measuredimpedance is within acceptable limits, energy continues to be applied tothe tissue.

The control of the delivery of a cooling solution to RF electrode 122and/or tissue site 112 is done in the following manner. During theapplication of energy, temperature measurement device 150 measures thetemperature of tissue site 112 and/or RF electrode 122. A comparator 166receives a signal representative of the measured temperature andcompares this value to a pre-set signal representative of the desiredtemperature. If the tissue temperature is too high, comparator 166 sendsa signal to a flow regulator 160 (connected to an electronicallycontrolled micropump, not shown) representing a need for an increasedcooling solution flow rate. If the measured temperature has not exceededthe desired temperature, comparator 166 sends a signal to flow regulator160 to maintain the cooling solution flow rate at its existing level.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. Obviously, many modifications and variations will be apparentto practitioners skilled in this art. It is intended that the scope ofthe invention be defined by the following claims and their equivalents.

1. A sphincter treatment apparatus comprising: an elongated memberhaving at least one lumen including an inflation lumen, a basketassembly including a first and a second arm, at least one of the firstand second arms including a fluid lumen having an aperture for conveyinga fluid from the basket assembly, the basket assembly being coupled tothe elongated member and having a deployed and a non-deployedconfiguration, an inflatable member coupled to the elongated member andpositioned in an interior of the basket assembly, the inflatable memberbeing coupled to the inflation lumen, the inflatable member having adeployed and a non-deployed state, wherein in the deployed state theinflatable member expands the basket assembly to the basket assemblydeployed configuration, and an energy delivery device coupled to thebasket assembly and configured to be advanceable into tissue to deliverenergy to a selected treatment site.
 2. The apparatus of claim 1 whereinthe energy delivery device is positioned on an exterior surface of thebasket assembly.
 3. The apparatus of claim 1 wherein the energy deliverydevice is integral to the basket assembly.
 4. The apparatus of claim 1wherein the energy delivery device is disposed in the basket assembly.5. The apparatus of claim 4 wherein the energy delivery device isdisposed on an interior surface of the basket assembly.
 6. The apparatusof claim 1 wherein the energy delivery device includes a tissue-piercingdistal end.
 7. The apparatus of claim 6 wherein the energy deliverydevice is a radiofrequency electrode.
 8. The apparatus of claim 7wherein the radiofrequency electrode is a needle electrode.
 9. Theapparatus of claim 7 wherein the energy delivery device includes aplurality of radiofrequency electrodes.
 10. The apparatus of claim 1wherein the fluid is a cooling fluid.
 11. The apparatus of claim 10wherein the fluid cools tissue adjacent the energy delivery device. 12.The apparatus of claim 10 wherein the fluid cools the energy deliverydevice.
 13. The apparatus of claim 1 wherein the energy delivery deviceis advanceable from the at least one arm through the aperture.
 14. Theapparatus of claim 1 wherein the fluid is an electrolytic solution.